Locations of TLR4 in healthy dental pulp tissue and dental pulp tissue affected by deep caries

To analyze the role of TLR4 in innate immune response of dental pulp by comparing the locations and expressions of TLR4 in healthy dental pulp tissue and dental pulp tissue affected by deep caries.

Healthy teeth and teeth affected by deep caries were demineralized and stained with hematoxylin and eosin (HE) to observe the morphology of dental pulp. Immunohistochemistry staining was performed to observe the expressions of TLR4.

Observed under HE staining, dentin tubules of teeth affected by deep caries were damaged with a lot bacteria mass. The expression of TLR4 were located in the odontoblast layer and near the blood vessels in both groups. Positive staining of TLR4 in deep caries pulps (2.10±0.74) were significantly higher than that in healthy teeth (1.25 ± 0.46).

Expression of TLR4 in deep caries pulp is stronger than that in healthy pulp. It suggests that TLR4 may play a role in the innate immune response of deep caries.